Cataract surgery is commonly performed on an eye in which an originally clear, natural crystalline lens has become cloudy or opaque due to factors such as aging, prolonged exposure to radiation, or certain medical conditions. To provide vision correction to the affected eye, an artificial intraocular lens (IOL) is inserted adjacent or is used to replace the natural crystalline lens. Typically, IOLs are made up of an optically clear lens or “optic” that is secured in position within the eye via one or more flexible fixation members or “haptics”. The haptics extend from the optic, and each haptic affixes directly to the eye.
Prior to surgery, the IOL is placed within an insertion device configured to deliver the IOL to the eye. In particular, the IOL is positioned within a load chamber of a cartridge of the insertion device. The load chamber defines a first lumen for receiving the IOL so that when the IOL is positioned therein, the cartridge may be manipulated to thereby roll, fold, or otherwise compress the IOL into a desired shape. An elongated inserter tube portion of the insertion device includes a second, tapered lumen adjacent and in communication with the first lumen for facilitating the passage of the folded IOL toward an exit of the insertion tube.
During surgery, a small incision of about 1-4 mm is made in the patient's eye. Preferably, the incision is as small as possible to reduce healing time. In some cases, a tool is inserted into the incision to emulsify the patient's natural lens. The emulsified material is then vacuum-suctioned from the eye. A tip of the insertion device is placed into the incision and the IOL is urged into the first lumen to be compressed or folded. As the IOL travels from the first lumen to the second lumen of the elongated inserter tube, the IOL is further compressed, rolled or otherwise manipulated into smaller dimensions suitable to pass through the 1-4 millimeter (mm) incision. The IOL then slips into the eye through the incision and automatically unfolds therein. In cases in which the natural lens remains in the eye, the folded or compressed IOL is placed adjacent the natural lens.
To ensure that the IOL is intact post-delivery, the inner surfaces of the cartridge and the elongated inserter tube are coated with a lubricity enhancing material to reduce an amount of force needed to pass the IOL through a small diameter of the insertion tube exit. Though damage to the IOL is rare when passed through the insertion tube exit, a mechanism to ensure lubricity of the cartridge's lumen and tip is adequate and uniform across the cartridge inner surface is desirable.